Diphenyl ether herbicidal compositions

ABSTRACT

WHEREIN X and Y are as defined above. WHEREIN X and Y are defined above, with a p-nitrohalogenobenzene at an elevated temperature in the presence of a deacidifying agent. A new herbicidal composition comprising a herbicidal amount of at least one compound represented by the formula,   WHEREIN X and Y are individually a fluorine or chlorine atom, provided that X is a fluorine atom when Y is a fluorine atom and is a fluorine or chlorine atom when Y is a chlorine atom, which are prepared by reacting a pentahalogenophenol having the formula,   Novel diphenyl ether derivatives having the formula,

United States Patent 1191 Nagatomi et al.

1451 May21, 1974 DIPHENYL ETHER HERBICIDAL COMPOSITIONS lnventors': Makoto Nagatomi; Takayuki lso gawa; Nobuo Onodera, all of Tokyo; Nobuo Ishikawa, Yokohama, all of Japan Hodogaya Chemical Co.', Ltd., Tokyo, Japan Filed: Dec.'27, 1971 7 Appl. No.: 212,624

Assignee:

11s. 71/124, 260/612 D 1111. c1 A01n 9/24 Field of Search 71/124; 260/612 D [5 6] References Cited UNITED STATES PATENTS 3,401,031 9/1963 lnoueetal ..71/124 3,454,392, 7/1969 K111 61111...

3,131,166 4/1964 Harris'et al... 71/124 3,351,670 11/1967 Belf...., 260/612 R FOREIGN PATENTS OR APPLICATIONS 15,000 8/1966 Japan 71/124 OTHER PUBLICATIONS Yakobson et al., Aromatic Nucleophilic Substitution etc., (1967), CA 68, No. 2l346m (1968).

Primary Examiner-Glehnon H. Hollrah Attorney, Agent, or Firm-Ladas, Parry, Von Geh r, Goldsmith & Deschamps 1 [57] ABSTRACT Novel diphenyl ether derivatives having the formula,

wherein X and Y are individually a fluorine or chlorine atom, provided that X is a fluorine atom when Y is a fluorine atom and is a fluorine or chlorine atom when Y is a chlorine atom, which are prepared by reacting a pentahalogenophenol having the formula,

- wherein X and Y are defined above, with a p-nitrohalogenobenzene at an elevated temperature in the presence of a deacidifying agent.

A .new herbicidal composition comprising a herbicidal amount of at least one compound represented by the formula,

wherein X and Y are as defined above.

9 Claims, No Drawings DIPHENYL ETHER HERBICIDAL COMPOSITIONS .dichloro-2,3,6 trifluorophenyl 4-nitrophenyl ether.

Heretofore, herbicidal compositions containing various compounds as active ingredients have been developed and put into practical use. In actual application, however, not many of said compositions satisfy all of various conditions required for crop cultivation. For example, diphenyl ether type compounds have been developed in large numbers and, as the result of examination in herbicidal activity thereof, some of them are being used in practice. These compounds are ordinarily used 'asactive ingredients in amounts of 200 to 400 g.

per ares. However, they are not only short in suit- I able application period but also are less in persistence of activity. Moreover, they have such drawbacks as being somewhat. low in herbicidal activity on such braod-leaved weeds as m onochoria (Monochoria vaginalis), etc", and the actual state is such that the said compounds are not satisfactory in practical application. 1

With an aim to obtain strong herbicidal compositions capable of satisfying the above-mentioned conditions,

.the present inventors synthesized many compounds and examined their activities on plants to 'find that the compounds according to the present invention have extremely strong herbicidal activities. Basedon this finding, the inventors have accomplished the present invention.-

An object of the present invention is to provide novel compounds.

Another object of the invention is to provide herbicidal compositions containing said compounds as active ingredients. iv

A further object of the invention is to provide a process for killing-undesirable weeds by use of said herbicidal compositions; The compounds of the present inventionare diphenyl ether derivatives represented by' the formula,

wherein and aiaaarnaiiaiy Antonie or 5mm I atom, provided that X is a fluorine atom when Y is a fluorine atom and is a fluorine or chlorine atom when Y is a chlorine atom.

The present compounds are novel compounds unknown to the literature and canbe prepared according to a process carried out byrea'cting in the presence of a deacidifying agent and at an'elevated temperature (a) a hexahalogenobenzene represented by the formula,

wherein X and Y are as defined above, with pnitrophenol, or (b) a pentahalogenophenol represented by theformula,

wherein X and Yare as de fined above, with a pnitrohalogenobenzene.

in preparing the present compounds, the hexahalogenobenz'ene represented by the formula (I) and the p-nitrophenol, or the pentahalogenophenol represented by the general formula (2) and the pnitrohalogenobenzene, are dispersed in water or dissolved in a solvent, and the resulting dispersion or solvent is incorporated with an equivalent or excess of a deacidifying agent and then reacted at an elevated temperature above room temperature. Alternatively, the present compounds can be obtained, without the use of solvent, by reacting at an elevated temperature a salt of each of the above-mentioned phenols with each of the halides to be reacted therewith.

As the aforesaid solvent, there may be used such a polar solvent as ketone, dimethylformamide, dimethyl sulfoxide or dioxane, or such a solvent as toluene or chlorobenzene. Generally howeventhe use of the polar solvent is preferable. The amount of the polar solvent to be used is not particularly limited, but is ordinarily 2 to 10 times the weight of the phenol used. As the said deacidifying agent, such an inorganic base as potassium hydroxide, sodium hydroxide, potassium carbonate, so-

- dium carbonate or sodium bicarbonate, or such an organic base as a tertiary amine may be used, but the use of the former is preferable. The reaction temperature varies depending on the kinds of said solvent and deacidifying agent and on the combination of the aforesaid phenol and halide, but is ordinarily in the range from 30f to C. in the reaction of hexahalogenobenzene with p-nitrophenol, and in the range of from 90 to C. in the reaction of pentahalogenophenol with p-nitrohalogenobenzene. In case the halogen in the pnitrohalogenobenzene is a chlorine atom, the conversion is inferior, in general, and the use of pnitrofluorobenzene is preferable. The reactants may be used in equimolar amounts, or either one of them may be used in excess. The reaction time greatly varies depending on the reaction conditions, but is sufficiently 3 to 6 hours when the conditions are favorable.

Compounds obtained according to the abovementioned process are as follows:

F F a F O NO. m... We.

. F F v a o @m m... M... I F 031 According to application purposes, the herbicidal compositions of the present invention can be formulated into preparations capable of being widely usable as agricultural chemicals, such as granules, emulsifiable concentrates, wettable powders, etc. These preparations can be formulated according to ordinary agricu1-' Procedures for synthesizingthe present compounds are explained below with reference to examples.

EXAMPLE 1 1 A mixture comprising 30 g. of pentafluorochlorobenzenc, 21 g. of p-nitrophenol, 42 g. of powdery potassium carbonate and 200 ml. of dimethylformamide was fed to a reaction flask, and then reacted with thorough stirring for 3 hours while maintaining the reaction temperature at 75 to 80C. Subsequently, the reaction liquid was poured into 3 liters of water to liberate an oily substance. This oily substance was extracted with 300 ml. of benzene, washed with water and dehydrated, and then the benzene was removed, whereby 36 g. of crude crystals having a melting point of 76 to 80C. was obtained. The crude crystals were recrystallized from ethanol to obtain crystals of 4-chlorophenyl-2,3,5,6- tetrafluorophenyl 4-nitropheny1 ether having a melting point of 80 to 82C.

Elementary analysis:

According to NMR analysis, two double lines were observed at +66.4 ppm. and +79.3 p.p.m., but this showed that there were two fluorine atoms equal in valence, and it was confirmed that the product had the desired structure.

EXAMPLE 2 A mixture comprising 30 g. of p'entafluorochlorobenzene, 19 g. of p-nitrophenol, 42 g. of powdery potassium carbonate and 300 ml. of dioxane was fed to a reaction flask, and then maintained with thorough stirring at 90 to 100C. for 5 hours. Thereafter, the reaction liquid was treated in the same manner as in Example 1 to obtain 33 g. of a crude crystalline produce having a melting point of 77 to 80C. According to infrared analysis, it was-confirmed that the product was identical with that obtained in Example 1.

EXAM PLE 3 A mixture comprising 18.6 g of hexafluorobenzene, 13.9 g. of p-nitrophenol, 30 g. of powdery potassium carbonate and 200 ml. of dimethylformamide was fed to a reaction flask, and then reacted for 6 hours with thorough stirring while maintaining the mixture at to C. Thereafter, the reaction liquid was treated in the same manner as in Example 1, whereby 15 g. of crude crystals having a melting point of 57 to 61C. was obtained. The thus obtained crude crystals were recrystallized from methanol to obtain pentafluorophenyl 4-nitrophenyl ether having a melting point of 60 to 63C.

Elementary analysis:

A mixture comprising 21.9 g. of 2,4,5,6-tetrafluoro- 1,3-dich1orobenzene, 12.5 g. of p-nitrophenol, 20 g. of powdery sodium carbonate and ml. of dimethylformamide was fed to a reaction flask, and then reacted with thorough stirring at 70 to 75C. for 3 hours. Subsequently, the reaction liquid was poured into 1 liter of water to liberate an oily substance. This oily substance was isolated, subjected to steam distillation, and then cooled, and the residue was recovered by filtration, washed with water and then dried, whereby 20 g. of crystals having a melting'point of 98 to 101C. were obtained. The thus obtained crystals were recrystallized from ethanol to obtain 2,4-dichloro-3,5,6- trifluorophenyl 4-nitrophenyl ether having a melting point of 100 to 102C.

Elementary analysis:

Found Bentonite EXAMPLE 5 A mixture comprising 21.1 g. of 2,4,5,6-tetrafluoro- 1,3-dichlorobenzene and 16 g. of potassium salt of pnitrophenol was fed to a reaction flask, and then reacted with thorough stirring at 100 to 110C. for 5 hours. Thereafter, the reaction liquid was treated in the same manner as in Example 4, whereby g. of crystals having a melting point of 97 to 100C. were obtained. The thus obtained crystals were recrystallized from ethanol to obtain a crystalline product having a melting point of 100 to 102C. This product was mixed with the product. obtained in Example 4, but no melting point depression was observed.

EXAMPLE 6 A mixture comprising 19.3 g. of 4-chloro-2,3,5,6- tetrafluorophenol, 13.9 g. of p-n'itrofluorobenzene, 100 ml. of dimethylformamide and g. of powdery potassium carbonate was fed to a reaction flask, and reacted with thorough stirring at 120? to 130C. for 3 hours. Thereafter, the reaction liquid was poured into 1 liter of water to liberate an oily substance. This oily substance was isolated, subjected to steam distillation and then cooled, and the residue was recovered by filtration, washed with water and dried, whereby 12 g. of crystals having'a melting point of 78 to 80C. were obtained. The thus obtained crystals were mixed with the product obtained in Example 1, but no melting point depression was observed.

Procedures for formulating the present herbicidal compositions are explained below with reference to examples, but the scope of the invention is not limited to the examples.

The above-mentioned components were mixed and dissolved together to obtain an emulsifiable concentrate of the present compound.

EXAMPLE 8 Presentcompound (No. 3) 50 parts by weight White carbon i 2 do.

Kaolin clay 43 do.

Sorpol 5039 (trademark of i Toho Chemical Co.) I 5 The above-mentioned components were pulverized and mixed'together to obtain, a wettable powder of the present compound.

EXAMPLE 9 Present compoundthlo. 3) I 5 parts by weight Talc 41 do.

Pellex OTP (trademark of Kao Atlas Co.) 4 do.

The above-mentioned components were pulverized and mixed together, kneaded with water and then granulated by means of a granulator to obtain a granule of the present compound.

EXAMPLE l0 Present compound (No. 2) 5 parts by weight Finely-divided bentonite 40 do.

do. zeolite 51 do.

Pellex OTP (trademark of Kao Atlas Co.) 4 do.

The present compound and Pellex OTP were dissolved in acetone, and the resulting solution was coated by means of a speed kneader on a mixture of the abovementioned finely divided bentonite and finely divided zeolite to obtain a fine granule preparation of the present compound.

Activities of the present compounds on plants are illustrated below with reference to examples.

EXAMPLE ll In each of glass Petri dishes of 9 cm. in diameter were placed two qualitative filter papers as germination bed. Separately, each of the compounds according to the present invention and, as controls, pentachlorophenyl 4-nitrophenyl ether (hereinafter referred to as PCDE), and 2,4,6-trichlorophenyl 4-nitrophenyl ether (hereinafter referred to as 'MO) and 2,4- dichlorophenyl 4-nitrophenyl ether (hereinafter referred to as NlP) which are active ingredients of known herbicides, was dissolved in a l 1 mixture of xylene and cyclohexanone. The resulting solution was incorporated with Sorpol 800 A (trademark of Toho Chemical Co.) as an emulsifier to prepare a test emulsiv fiable concentrate. Subsequently, this emulsifiable concentrate was diluted so that the active ingredient concentration thereof became each of 250, 100, 50, 25, 10, 5, 2.5 and 1 ppm, and 15 cc. ofthe resulting composition was charged into the aforesaid Petri dish. Thereafter, seeds'of millet (Echinochloa crusgalli P. BEA UV. var. frumentaceae) as a typical Gramineae plant were sowed in the nursery and allowed to germinate and grow in, a growth cabinet kept at 30C. Five days after the sowing, the state of the plant in each area treated with the composition was visually investigated. The results obtained were as set forth' in Table l, in

Non-inhibition Table 1 Concentration (p.p.m.) 250 100 50 2s EXAMPLE 12 Test was effected by use of a test emulsifiable concentrate comprising the following components:

Upland field soil (diluvium clay loam) was packedinto l/5,000 are-Wagner pots. Into the soil were sowed to a suitable depth seeds of each of such plants as upland rice (Oryza satt'va L.), wheat (Triticum aestivum L.) azuki bean (P/taseolus angularis) and rape '(Brassica napus L.). Onthe other hand, seeds of such weeds as millet (Echinochloa crusgalli P. BEA U V. var. frumentacea) and clover (Trifolium repenus L.) were sufficiently mixed with previously sieved soil, and were uniformly covered on the soil in the pots to a surface layer of 0.5 cm. Subsequently, the aforesaid emulsifiable concentrate according to the present invention was diluted with water and uniformly applied to the soil surface so that the amount of the active ingredient became each of 20, I and 5 g. per are. For comparison, MO was formulated into an emulsifiable concentrate of the same composition as in the case of the present compound, and applied in the same manner as above. Thereafter, the pots were placed in a glass greenhouse and, on the 20th day after the application, the response of the plants was visually investigated. The results obtained were as set forth in Table 2, in which the figures have the following significances:

l0 Non-germination or iE plant withered after 7 A germination 8 Extremely great damage or marked decrease in germination ratio 6 Great damage 4 Medium damage 2 Slight damage 0 Non-damage Table 2 Test Dosage Response of plant chemical (g/ are) Rice Wheat Azuki Rape Millet Clover bean 20 3 3 4 4 l0 No. 2

5 0 0 0 0 9 7 2 2 3 l l0 10 No. 3

5 O O -0 0 9 6 20 3 3 2 2 6 0 MO EXAMPLE l3 Paddy field soil was packed into l/5,000 are'Wagner pots. Into the soil were sowed seeds of barnyardgrass (Echinochloa crusgalli). Further, soil containing seeds of needle spikerush (Eleocharis acicularis) was placed on the soil surface, and rice (Oryza sativa L variety: Nihonbare), which had previously been grown to the four-leaf stage, were transplanted into the soil. Subsequently, water was charged into each pot to a depth of 3 to 4 cm. After the rice plants had rooted, and aqueous dilution of each of the emulsifiable concentrate of Example 8 and an emulsifiable concentrate of MO as a control was charged into the water so that the amount of the active ingredient became each of 20, i0 and 5 g. per are. Thereafter, the pots were placed in a glass greenhouse and, on the 20th day after the application, the response of each plant was visually investigated. The results obtained were as set forth in Table 3, in which the figures have the same significances as in Table 2.

Table 3 Test Dosage compound (glare) Response of plant Ricc Barnyardgrass Necdlc spikerush Herbicidal effects of the present herbicidal compositions are illustrated below with reference to examples.

EXAMPLE l4 Pre-emergence soil treatment tests in upland field soil of alluvium clay loam were carried out in the following manner:

o-Nuh klt came eachof 40, 20.and 10 g. per are, and the resulting aqueous dilution was uniformly sprayed onto the soil surface. As a control, each of emulsifiable concentrates containing PCDE, MO and NIP was also applied in the same manner as above. On the 30th day after the application, the response of each plant was visually investigated. The results obtained were as set forth in Table 4, in which the figures have the following significances:

l transplantation, each of the granule of Example 9 and control granules of PCDE, MO and NIP was sprinkled by hand over the water surface so that the amount of the active ingredient became each of 20 and 15 g. per are. On the 30th day after the application or treatment, the response of each plant was visually investigated. The results obtained were as set forth in Table 5, in

which the figures have the same significances as in Table 4.

g eTiiii n aiiiiiii or the wnhered 10 As IS clear from the above examples, the compounds Extremely great damage of the present invention not only have extremely strong Great damage Medium damage Slight damage Non-dumagc Table 4 Test Dosage Response of plant chemical (g/are) Upland rice Peanut Soybean Millet Large White Colver crabgrass goosefoot 40 l o 2 4 4 2 3 No.1 20 i 0 0 0 3 3 O 0 l0 0 0 0 0 O 0 O 40 2 0 2 5 5 5 No. 2 20 l O l 5 5 5 5 l0 0 0 0 4 4.5 4 4 40 l 0 l 5 5 5 5 No. 3 2O O O 0 4.5 5 4.5 4.5

0 0 0 3 3' 4 4 40 0 0 0 '0 l 0 0 PCDE 0 0 0 0 0 0 0 l0 0 O 0 0 0 O 0 40 l 0 l 5 S 3 4 MO 20 0 0 l 3 3 l 2 l0 0 0 0 O 0 0 O 40 2 O 1 5 5 4 5 N]? 20 l 0 l 3 4 2 3 l0 0 0 0 l l O 0 Table 5 Test Dosage Response of plant chemical (g/are) Rice Barnyard grass Flat sedge Monochoria Toothcup Needle Spikerush 20 0 4 2 O 2 0 No. l

l5 0 2 0 0 l 0 20 0 5 5 5 5 5 No. 2

l5 0 S 5 4.5 5 4 20 0 5 5 4 5 4 No. 3

l5 0 5 5 3 5 3 20 0 0 0 0 0 0 PCDE l5 0 0 0 0 O 0 20 0 4.5 4.5 3 5 2 M0 l5 0 2 2 2 3 0 20 0 4.5 4.5 4 5" 3 NIP activities on plants but also are high m practical selec- EXAMPLE 15 tivity. Although the compounds of the present invenlnto a concrete of grown to the. fiveto six-leaf stage, were transplanted to the soil, andwater was charged into the concrete frame to a depth of 4 cm. On the 4th'day after the tion show usefulness as herbicides, it is the great characteristic of the present compounds that they have strong activities on plants. Further, the present compounds are particularly preferable as herbicides for use in preemergence treatment. Moreover, another characteristic of the present compounds as compared with other compounds lies in that they have extremely strong herbicidal activities. Considering the fact that pentachlorophenyl 4-nitrophenyl ether has little herbicidal activ- 1 1 ity, it is quite surprising that the present compounds, which belong to the category of pentahalogenophenyl derivatives identical with said compound, have strong activities.

What is claimed is:

l. A herbicidal composition comprising an inert diluent or carrier and a herbicidally effective amount of an active ingredient selected from the group consisting of compounds represented by the formula wherein X and Y are individually a fluorine or chlorine atom, provided that at least one of X or Y is a chlorine atom.

5. A wettable powder composition comprising an inert powder containing a surfactant and. an effective amount of a herbicidally active ingredient selected from the group consisting of compounds represented by the formula wherein X and Y are individually a fluorine or chlorine atom, provided that at least one of X or Y is a chlorine atom.

6. A granular composition comprising inert granules and an effective amount of a herbicidally active ingredient selected from the group consisting of compounds represented by the formula wherein X and Y are individually a fluorine or chlorine atom, provided that at least one of X or Y is a chlorine atom.

7. A method for controlling weeds comprising applying to an area selected for weed control a herbicidally effective amount of a compound represented by the formula wherein X and Y are individually a'fluorine or chlorine atom, provided that at least one of X or Y is a chlorine atom.

8. A method according to claim 4 wherein there is applied 4-chloro-2,3,5,6-tetrafluorophenyl nitr'ophenyl ether.

9. A method according to claim 4, wherein there is applied 4,6-dichloro-2,3,S-trifluorophenyl 4- nitrophenyl ether.

Patent No. a

Datedmp1 Inventor(s) It is certified that error appears in "the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the Forei@ Application Priority Beta, the

number "11937" should read. M9397 Signed and sealed this 5th day of November 1974.

(SEAL) Attest:

McCOY M. GIBSON JR. C. MARSHALL DANN Attesting Officer Commissioner of Patents FORM PC4050 (10-69) USCOMM-DC 60376-1 69 11.5 GOVERNMENT PRINTING OFFICE: mm 0-365-334, 

2. A herbicidal composition according to claim 1, wherein the compound is 4-chloro-2,3,5,6-tetrafluorophenyl 4-nitrophenyl ether.
 3. A herbicidal composition according to claim 1, wherein the compound is 4,6-dichloro-2,3,5-trifluorophenyl 4-nitrophenyl ether.
 4. AN emulsifiable concentrate comprising an inert liquid diluent and an effective amount of a herbicidally active ingredient selected from the group consisting of compounds represented by the formula
 5. A wettable powder composition comprising an inert powder containing a surfactant and an effective amount of a herbicidally active ingredient selected from the group consisting of compounds represented by the formula
 6. A granular composition comprising inert granules and an effective amount of a herbicidally active ingredient selected from the group consisting of compounds represented by the formula
 7. A method for controlling weeds comprising applying to an area selected for weed control a herbicidally effective amount of a compound represented by the formula
 8. A method according to claim 4 wherein there is applied 4-chloro-2,3,5,6-tetrafluorophenyl 4-nitrophenyl ether.
 9. A method according to claim 4, wherein there is applied 4,6-dichloro-2,3,5-trifluorophenyl 4-nitrophenyl ether. 